Clear blisters? Pic.

So for the 2nd time during my pregnant(it's my 1st) I   have had these odd clear blisters on my bottom inner lip. They do not hurt like a canker sore would. If I pop it a clear liquid comes out of them. But again no pain.  Just more of an annoying thing. 
I thought the first time was maybe the ribs I was eating were too hot bc the next day I woke up with them. 
Today I had got oatmeal and noticed them too(just not sure if they were there before I ate it)
Anyone else getting these????
I'm 26 weeks as of this coming Monday. 
Is it pregnancy related? Or do you think it's just a coincidence of eating something hot.